An ideal inextensible string is wrapped over the disc of mass m and radius R. The other end of the string is connected to mass m. the string is passing over an ideal pulley A as shown in the figure. At any time t, mass m and disc are moving downward with acceleration of magnitude `a_(1) " and " a_(2)` respectively. The disc is rotating clockwise with angular acceleration of magnitude ` alpha` . There is no slipping betweeb string and disc. choose the incorrect option
A. `a_(1)=a_(2)`
B. `alphaR gt a_(1)`
C. `alpha R=a_(1)`
D. `alphaRlta_(2)`